Prevalence of megabacteria in budgerigar colonies     

LJ FILIPPICH  JK HENDRIKZ 《Australian veterinary journal》1998,76(2):92-95

Objective To measure the prevalence of megabacteria in budgerigar-breeding colonies and to evaluate possible methods to reduce the prevalence.
Design A monitoring study over several years.
Sample population Two budgerigar ( Melopsittacus undulatus ) colonies with over 300 birds each.
Procedure The prevalence of megabacteria in the faeces in two budgerigar breeding colonies, colony 1 and 2, was determined by faecal examination of each bird. Following an initial survey (1990), most of the birds that were scored 2+ or more were culled and a management practice was implemented to discriminate against positive birds. Consecutive yearly surveys (1991, 1992) were conducted on the young birds bred in these colonies. The prevalence of megabacteria in colony 2 was also evaluated in 1994 and 1996 after all the birds were treated with amphotericin B administered in drinking water.
Results The prevalence of megabacteria in the two colonies was significantly (P < 0.001) different. Overall the prevalence of megabacteria adjusted for colony differences was significantly higher (P < 0.025) in males compared to females. Age was not an influencing factor. After the initial survey, the prevalence in the offspring did not significantly (P > 0.05) decrease in the following two annual breeding seasons but by inference it did significantly decrease after amphotericin B treatment.
Conclusion The practice of culling most birds with more megabacteria in faeces and discriminating against positive birds when selecting birds for breeding or culling birds on show quality does not decrease megabacteria prevalence in the offspring. However, a reduction in prevalence does occur with administration of amphotericin B. Birds may have amphotericin B-resistant organisms and these birds need to be identified and culled.  相似文献   

Physiological Responses of Rainbow Trout Oncorhynchus mykiss to Crowding and Anesthesia with AQUI-S™     

Glen W.  Davidson Peter S.  Davie Graham  Young Reece T.  Fowler 《Journal of the World Aquaculture Society》2000,31(1):105-114

Abstract.— Following exposure to the anesthetic AQUI-S™, plasma cortisol concentration in immature rainbow trout was measured as (mean) 293 ± 48 ng/ mL, which was significantly ( P > 0.05) higher than the mean concentration in resting fish. Cortisol concentrations remained significantly ( P > 0.05) elevated for at least 24 h after treatment. This was accompanied by a significant increase and decrease in hematocrit and plasma potassium, respectively. These perturbations continued for at least 48 h following recovery from anesthesia. Plasma concentrations of total protein and sodium remained unchanged following anesthesia with AQUI-S™. Crowding stress is commonly encountered by fish during manipulation in aquaculture situations. Anesthetising fish prior to, and during, manipulation may reduce the associated stress. Changes in cortisol values resulting from crowding (30 min; 0.1 kg/L) during anesthesia with AQUI-S™ were not appreciably different from those in fish crowded without anesthesia. Thus, anesthesia with AQUI-S™ at the recommended dose of 17 mg/L did not appear to be effective for alleviating the stress of crowding under the conditions of our experiments.  相似文献   

Cochlosoma infections in finches     

LJ FILIPPICH  PJ O'DONOGHUE 《Australian veterinary journal》1997,75(8):561-563

Objective To survey finches in pet shops for Cochlosoma infection and evaluate the efficacy of antiprotozoal therapy with metronidazole or ronidazole.
Design A survey of pet shop finches and drug efficacy trials.
Procedure Finches in pet shops were randomly selected and their faeces examined microscopically for motile Cochlosoma sp trophozoites. Drug trials were carried out on 60 adult finches with naturally occurring infections. Body weight was measured and the faeces of each bird was examined for trophozoites at the beginning and 7 days after the end of treatment. In some birds, additional daily faecal examinations were done until three consecutive negative results were obtained. Metronidazole was administered at various dose rates by crop gavage or in drinking water to eight groups of five to ten finches each. Ronidazole was given in water for 7 days to ten finches. In addition, six finches whose faeces tested positive were necropsied and their tissues collected for histological examination.
Results Motile flagellates in the faeces were identified as C anatis -like protozoa. Red-headed parrot-finches, Bengalese and Lady Gould finches were found to be most commonly infected. Cochlosoma sp was also found in the blue-faced parrot-finch, zebra finch, painted finch, nutmeg mannikin and double-barred finch. Metronidazole and ronidazole were found to be effective against Cochlosoma sp. Histological findings on infected adult finches were normal, except for the presence of numerous flagellates between the colorectal villi and cloacal mucosal folds.
Conclusions Cochlosoma anatis -like organisms can infect several species of finches and in adult finches are confined to the colorectum and cloaca. Infection in adult finches was mostly subclinical and could be treated effectively with metronidazole or ronidazole.  相似文献   

The pathogenesis of velogenic Newcastle disease virus infection of chickens of different ages and different levels of immunity   总被引：2，自引：0，他引：2  

L Parede  P L Young 《Avian diseases》1990,34(4):803-808

Chickens of 7 weeks or 20 weeks of age were divided into three groups according to their antibody status (high, low, absent) and were infected with a velogenic viscerotropic Newcastle disease virus. To follow patterns of viral replication, birds were necropsied at regular intervals up to 22 days and organs were sampled from each bird. In non-immune birds, virus could be isolated from all organs examined. In birds with antibody, virus was most frequently isolated from the proventriculus, cecal tonsil, bursa, and brain. However, because no one organ could be recommended for all situations, all four should be sampled for field diagnosis. In immune birds, although clinical signs were either mild or absent, widespread virus replication occurred up to 19 days post-challenge.  相似文献   

Effect of ACTH on plasma corticosterone and cortisol in eagles and condors   总被引：1，自引：0，他引：1  

R D Zenoble  R J Kemppainen  D W Young  J W Carpenter 《Journal of the American Veterinary Medical Association》1985,187(11):1119-1120

The effect of ACTH on plasma corticosterone and cortisol was determined in 12 eagles (Haliaeetus leucocephalus) and in 6 Andean condors (Vultur gryphus). In all raptors, the concentration of plasma corticosterone was substantially greater than that of cortisol. After ACTH administration, the eagles had a marked increase (P less than 0.001) in plasma corticosterone concentrations, but not in plasma cortisol. Administration of saline solution did not induce increased plasma corticosterone concentrations in the eagles. The condors had a smaller increase (P less than 0.002) in plasma corticosterone concentrations after ACTH administration, as compared with that of the eagles. However, administration of saline solution in 2 condors resulted in an increase in corticosterone similar to the increase after ACTH administration. In the condor, a stress-related release of endogenous ACTH may have an effect similar to that induced by exogenously administered ACTH. Plasma cortisol concentrations did not increase significantly after administration of ACTH or saline solution in either raptor species.  相似文献   

Jackknife method for estimating the variance of the age composition using two-phase sampling with an application to commercial catches of swordfish (Xiphias gladius)     

Hugo Robotham  Zaida I. Young  Juan C. Saavedra-Nievas   《Fisheries Research》2008,93(1-2):135-139

An estimate of the age composition of a commercial swordfish catch and its variance was obtained using the replicate full jackknife estimator for two-phase sampling where the sampling units in the first phase are clusters (vessel-trips) and the units of the second phase are individual fishes. The jackknife variance estimator was compared with an analytical estimator of variance commonly used in fisheries studies which ignores the clustering, and assumes simple random sampling of individual fish. The application of these naïve estimators to the Chilean South Pacific swordfish fishery results in an underestimation of the variance. This is a consequence of using an inappropriate primary sampling unit of analysis in the first-phase sample where the vessel-trip unit is replaced by an individual fish unit, thus ignoring the intra-cluster correlation in age samples. The jackknife estimator of variance is an alternative useful for complex two-phase sampling designs.  相似文献   

Cardiorespiratory responses to electrical stimulation of the buccal mucosa in ponies   总被引：1，自引：0，他引：1  

S S Young 《Research in veterinary science》1990,49(3):268-274

The cardiovascular and respiratory responses to electrical stimulation of the buccal mucosa under general anaesthesia in ponies were measured in order to provide some insight into the cardiorespiratory effects of anaesthesia in equidae. This knowledge may be useful for reducing morbidity during clinical anaesthesia in horses. Anaesthesia was induced with intravenous thiopentone and maintained with 1.3 per cent inspired halothane in oxygen. Arterial blood pressure, heart rate, minute volume, tidal volume, respiratory rate, arterial blood gas tensions and clinical signs of anaesthetic depth were recorded while the buccal mucous membrane was stimulated electrically. A rise in arterial blood pressure was the most consistent response detected along with clinical signs. The response of individual animals varied considerably. Alterations of respiratory pattern sometimes occurred during stimulation but there was no consistent pattern of change in any animal.  相似文献   

The effect of temperature on the energy budget of the Manila clam, <Emphasis Type="Italic">Ruditapes philippinarum</Emphasis>     

Kyung Nam Han  Soon Woo Lee  Soon Young Wang 《Aquaculture International》2008,16(2):143-152

In this study, the energy budget of the Manila clam, Ruditapes philippinarum, was evaluated after one-week acclimation periods at 5, 10, 15, 20, and 25°C. Small clams (151 ± 12 mg DW) and large clams (353 ± 16 mg DW) were fed with the microalgae, Isochrysis galbana. Filtration rate, ingestion rate, assimilation efficiency, oxygen-consumption rate, and ammonia excretion rate were measured. Both filtration rate and ingestion rate of small and large clams were found to be related to temperature. The highest Q ₁₀ values were measured in the range 15–20°C for both small and large clams. Assimilation efficiency of both small and large clams was not significantly influenced by temperature, although the maximum mean values were detected at 20°C. Oxygen consumption rate and ammonia excretion rate of small and large clams were found to be related directly to temperature over the entire range, with a maximum being detected at 25°C. The highest Q ₁₀ value was estimated in the range 10–15°C with regard to oxygen consumption rate, and in the range of 15–20°C with regard to ammonia excretion rate. Scope for growth (SFG) was positive at all temperatures, achieving a maximum value at 20°C in both small and large clams, primarily as a consequence of the enhanced ingestion rate which offset the concomitant elevation in the metabolic rate. In this study we have estimated the thermal optimum for this species at 20°C.  相似文献   

Sun injury to cut potato seed     

W. C. Edmundson  C. F. Clark  C. H. Metzger  J. C. Miller  Wm Stuart  L. C. Young 《American Journal of Potato Research》1939,16(4):98-104

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The characteristics of European,Mediterranean and other populations of white clover (Trifolium repens L.)     

W. Ellis  Norman R. Young 《Euphytica》1967,16(3):330-340

Indigenous populations of white clover (Trifolium repens L) collected from Europe, the Mediterranean area, as well as other parts of the world have been grown as spaced plants at Aberystwyth. Data were collected on various morphological characters, green weight and leaf marks.Leaflet length, width, area, plant height and green weight were all strongly correlated, but not the flowering date or leaflet shape (= ratio length/width).The mean leaflet size of Mediterranean populations (the supposed centre of origin) was very variable, and decreased northwards. All British populations were uniformly small leaved.Most of the populations were much less vigorous than the bred control varieties and only a few equalled them. Nevertheless some of the introductions exhibited seasonal growth patterns, especially growth into the autumn, and large leaves that could be usefully incorporated in improved varieties. Populations originating one step back towards the centre of origin will probably be the most useful when immediate adaptation is the aim.  相似文献